Valve construction having multiple piston means and method of making the same

Abstract

A valve construction having a housing provided with a chamber and ports leading to the chamber and having an axially movable piston unit disposed in the chamber to interconnect certain of the ports together in relation to the axial position of the piston unit that is caused by a condition responsive device and a spring operatively associated with the piston unit, the piston unit comprising a plurality of pistons disposed in spaced substantially parallel relation and being secured together to be axially moved in unison in the chamber under the influence of the condition responsive device. The spring comprises a single coiled compression spring telescopically receiving the pistons therein, the pistons being of different lengths.

What is claimed is: 
     
       1. In a self-contained temperature responsive valve construction having a housing means provided with a pair of ports separated by a first valve seat means that is opened and closed by a valve member means in response to temperature sensed by a piston and cylinder type temperature responsive device carried by said housing means and being operatively associated with said valve member means to control the same through axial movement thereof, the improvement wherein said housing means has a by-pass passage means therein separate from said valve member means and adapted to interconnect said pair of ports together independently of said first valve seat means when said first valve seat means is closed by said valve member means, and a one-way check valve means carried by said housing means and being separate from said valve member means for controlling said by-pass passage means to permit fluid flow between said ports through said check valve means in only one direction, one of said ports being disposed intermediate said first valve seat means and said one-way check valve means, said housing means having a second valve seat means disposed intermediate said one of said ports and said one-way check valve means to be controlled by said valve member means. 
     
     
       2. A valve construction as set forth in claim 1 wherein said one-way check valve means is disposed in aligned and spaced relation with said valve member means. 
     
     
       3. A valve construction as set forth in claim 1 wherein said housing means has restrictor means for fluidly interconnecting said ports together independently of said first valve seat means and said one-way check valve means. 
     
     
       4. A valve construction as set forth in claim 3 wherein said restrictor means is adapted to interconnect said ports together through said by-pass passage means. 
     
     
       5. A valve construction as set forth in claim 4 wherein said one of said ports is disposed intermediate said first valve seat means and said restrictor means. 
     
     
       6. A valve construction as set forth in claim 4 wherein said second valve seat means is also disposed intermediate said one of said ports and said restrictor means.